The present invention relates to an electrical switch that incorporates a small light to indicate the switched on condition.
Electrical switches of this type are known, in which the light often requires a resistor connected in series for proper operation. The resistor takes up space, and hence the size of the switch is inevitably increased. Added to this is the connection and fixing of the resistor that usually involve crimping or soldering during the assembly process.
The subject invention seeks to mitigate or at least alleviate such problems by providing an improved electrical switch of this type.
According to the invention, there is provided an electrical switch comprising a casing, at least three fixed contacts extending from inside to outside the casing, each of the contacts having an inner end portion, and an operating member supported within the casing for movement between an operating position and an inoperating position. The switch includes an internal moving contact movable by the operating member to make and break electrical connection between the inner end portions of a first pair of the fixed contacts while the operating member is in the operating and inoperating positions respectively. This pair of contacts is connectable to a load and a power source. Also included are an internal lighting element for lighting up to indicate when the operating member is in the operating position, and an internal resistor for the lighting element. The lighting element and resistor are connectable in series across the inner end portions of a second pair of the fixed contacts when the operating member is in the operating position. This pair of contacts is connectable to a power source. The resistor is located in a fixed position and has a body and first and second terminals. The first terminal comprises a contact pad provided on a surface of the body and in direct engagement with the inner end portion of one of the fixed contacts of the second pair for electrical connection therewith and being fixed in position.
Preferably, the inner end portion of the one fixed contact of the second pair has a part that protrudes laterally outwards and engages with the first switch terminal, with the resistor body lying adjacent and substantially parallel to the contact end portion.
In a preferred embodiment, the second resistor terminal comprises another contact pad which is provided on a surface of the resistor body and is in direct engagement with an electrical connector for connection to a first terminal of the lighting element.
More preferably, the resistor body has opposite end surfaces on which its two terminals are provided, and the resistor is clamped at its opposite terminals between the inner end portion of the one fixed contact of the second pair and a part of the connector.
Further more preferably, the resistor is located between the inner end portion of the one fixed contact of the second pair and the connector, in a substantially co-parallel manner.
In a specific construction, the lighting element is located within the operating member, including a second terminal that is connected to the moving contact.
More specifically, the first terminal of the lighting element is supported by the operating member for movement thereby to contact with the connector when the operating member is in the operating position.
It is preferred that in general, the lighting element is located within the operating member, and has a first terminal movable by the operating member for connection to the second terminal of the resistor when the operating member is in the operating position. The lighting element includes a second terminal connected to the moving contact.
Conveniently, the casing includes a slot receiving the resistor, both of which have practically the same cross-section.
It is preferred that the resistor body has a substantially flat rectangular configuration.
It is preferred that the resistor is a surface mounted device.
In a specific example, the electrical switch is a rocker switch, in which the operating member is supported for pivotal movement between the operating and the inoperating positions, and the moving contact is supported for pivotal movement by the operating member in opposite direction.